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      1 /*
      2  * Test whether process_vm_readv and PTRACE_PEEKDATA work.
      3  *
      4  * Copyright (c) 2016-2017 Dmitry V. Levin <ldv (at) altlinux.org>
      5  * Copyright (c) 2017-2018 The strace developers.
      6  * All rights reserved.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  * 3. The name of the author may not be used to endorse or promote products
     17  *    derived from this software without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     29  */
     30 
     31 #include "tests.h"
     32 
     33 #include <errno.h>
     34 #include <sys/ptrace.h>
     35 #include <signal.h>
     36 #include <stdlib.h>
     37 #include <unistd.h>
     38 #include <sys/uio.h>
     39 #include <sys/wait.h>
     40 
     41 #include "test_ucopy.h"
     42 
     43 #ifndef HAVE_PROCESS_VM_READV
     44 
     45 # include <asm/unistd.h>
     46 # include "scno.h"
     47 static ssize_t
     48 strace_process_vm_readv(pid_t pid,
     49 		 const struct iovec *lvec,
     50 		 unsigned long liovcnt,
     51 		 const struct iovec *rvec,
     52 		 unsigned long riovcnt,
     53 		 unsigned long flags)
     54 {
     55 	return syscall(__NR_process_vm_readv,
     56 		       (long) pid, lvec, liovcnt, rvec, riovcnt, flags);
     57 }
     58 # define process_vm_readv strace_process_vm_readv
     59 
     60 #endif /* !HAVE_PROCESS_VM_READV */
     61 
     62 static bool
     63 call_process_vm_readv(const int pid, long *const addr)
     64 {
     65 	long data = 0;
     66 
     67 	const struct iovec local = {
     68 		.iov_base = &data,
     69 		.iov_len = sizeof(data)
     70 	};
     71 	const struct iovec remote = {
     72 		.iov_base = addr,
     73 		.iov_len = sizeof(*addr)
     74 	};
     75 
     76 	return process_vm_readv(pid, &local, 1, &remote, 1, 0) == sizeof(data)
     77 		&& data == 1;
     78 }
     79 
     80 static bool
     81 call_ptrace_peekdata(const int pid, long *const addr)
     82 {
     83 	return ptrace(PTRACE_PEEKDATA, pid, addr, 0) == 1;
     84 }
     85 
     86 static bool
     87 test_ucopy(bool (*fn)(int pid, long *addr))
     88 {
     89 	static long data;
     90 
     91 	data = 0;
     92 	bool rc = false;
     93 	int saved = 0;
     94 
     95 	pid_t pid = fork();
     96 	if (pid < 0)
     97 		perror_msg_and_fail("fork");
     98 
     99 	if (!pid) {
    100 		data = 1;
    101 		if (ptrace(PTRACE_TRACEME, 0, 0, 0))
    102 			perror_msg_and_fail("PTRACE_TRACEME");
    103 		raise(SIGSTOP);
    104 		_exit(0);
    105 	}
    106 
    107 	for (;;) {
    108 		int status, tracee;
    109 
    110 		errno = 0;
    111 		tracee = wait(&status);
    112 		if (tracee != pid) {
    113 			if (errno == EINTR)
    114 				continue;
    115 			saved = errno;
    116 			kill(pid, SIGKILL);
    117 			errno = saved;
    118 			perror_msg_and_fail("wait");
    119 		}
    120 		if (WIFEXITED(status)) {
    121 			if (WEXITSTATUS(status) == 0)
    122 				break;
    123 			error_msg_and_fail("unexpected exit status %u",
    124 					   WEXITSTATUS(status));
    125 		}
    126 		if (WIFSIGNALED(status))
    127 			error_msg_and_fail("unexpected signal %u",
    128 					   WTERMSIG(status));
    129 		if (!WIFSTOPPED(status) || WSTOPSIG(status) != SIGSTOP) {
    130 			kill(pid, SIGKILL);
    131 			error_msg_and_fail("unexpected wait status %x",
    132 					   status);
    133 		}
    134 
    135 		errno = 0;
    136 		rc = fn(pid, &data);
    137 		if (!rc)
    138 			saved = errno;
    139 
    140 		if (ptrace(PTRACE_CONT, pid, 0, 0)) {
    141 			saved = errno;
    142 			kill(pid, SIGKILL);
    143 			errno = saved;
    144 			perror_msg_and_fail("PTRACE_CONT");
    145 		}
    146 	}
    147 
    148 	if (!rc)
    149 		errno = saved;
    150 	return rc;
    151 }
    152 
    153 bool
    154 test_process_vm_readv(void)
    155 {
    156 	return test_ucopy(call_process_vm_readv);
    157 }
    158 
    159 bool
    160 test_ptrace_peekdata(void)
    161 {
    162 	return test_ucopy(call_ptrace_peekdata);
    163 }
    164